Invasive Fish Threat To Kelp Forests
Seaweed-eating fish are becoming increasingly voracious as the ocean warms due to climate change and are responsible for the recent destruction of kelp forests off the NSW north coast near Coffs Harbour, research shows
(From Phys.org / by Deborah Smith)– The study includes an analysis of underwater video, covering a 10-year period between 2002 and 2012, during which the water warmed by 0.6 degrees.
“Kelp forests provide vital habitat for hundreds of marine species, including fish, lobster and abalone,” says study first author Dr Adriana Vergés of UNSW and the Sydney Institute of Marine Science.
“As a result of climate change, warm-water fish species are shifting their range and invading temperate areas. Our results show that over-grazing by these fish can have a profound impact, leading to kelp deforestation and barren reefs.
“This is the first study demonstrating that the effects of warming in kelp forests are two-fold: higher temperatures not only have a direct impact on seaweeds, they also have an indirect impact by increasing the appetite of fish consumers, which can devour these seaweeds to the point of completely denuding the ocean floor.
“Increases in the number of plant-eating fish because of warming poses a significant threat to kelp-dependent ecosystems both in Australia and around the globe,” she says.
The study has been published in the journal Proceedings of the National Academy of Sciences. The team recorded underwater video around August each year at 12 sites along a 25km stretch of coast adjacent to the Solitary Island Marine Park off northern NSW.
Read the full article here: http://phys.org/news/2016-12-invasive-fish-threat-kelp-forests.html#jCp